Method and apparatus for planarizing and cleaning microelectronic substrates

Abstract

A method and apparatus for mechanically and/or chemical-mechanically planarizing and cleaning microelectronic substrates. In one embodiment, a processing medium for planarizing and finishing a microelectronic substrate has a planarizing section with a first body composed of a first material and a finishing section with a second body composed of a second material. The first body may have a relatively firm planarizing surface to engage the substrate, and the first body supports abrasive particles at the planarizing surface to remove material from the substrate during a planarizing cycle. The second body may have a relatively soft buffing or finishing surface clean the abrasive particles and other matter from the substrate during a finishing cycle. The planarizing and finishing sections may be fixedly attached to a backing film or they may be attached to one another along abutting edges with or without the backing film. In one particular embodiment, the processing media may be an elongated web configured to extend between a supply roller and a take-up roller of a web-format planarizing machine having a plurality of individually driven substrate holders. The planarizing and finishing sections of this embodiment man be long strips of material extending lengthwise along a longitudinal axis of the web. The planarizing machine and elongated web may contemporaneously planarize and finish two or more substrates.

What is claimed is:  
     
       1. An apparatus for planarizing a semiconductor substrate, comprising: 
       a table with a stationary support base;  
       a processing medium attached to the stationary support base, the processing medium having a planarizing section extending lengthwise along the processing medium and a finishing section extending lengthwise along the processing medium which adjoins the planarizing section along a boundary extending longitudinally along the processing medium, the planarizing section having a first body composed of a first material and a relatively firm planarizing surface, the first body supporting abrasive particles at the planarizing surface to remove material from the substrate during a planarizing cycle, and the finishing section having a second body composed of a second material and a buffing surface softer than the planarizing surface to clean the substrate during a finishing cycle; and  
       a carrier assembly having at least a first substrate holder positionable over the stationary processing medium, the first substrate holder engaging the substrate with the planarizing section during the planarizing cycle, and the first substrate holder moving the substrate to the finishing section at the same work-station and engaging the substrate with the finishing section in the presence of a cleaning fluid during the finishing cycle.  
     
     
       2. The planarizing machine of  claim 1 , further comprising a plurality of planarizing sections and finishing sections with a lengthwise dimension extending transverse to a longitudinal axis of the processing medium and arranged in a pattern in which the planarizing and finishing sections alternate with one another along the longitudinal axis of the processing medium. 
     
     
       3. The apparatus of  claim 1  wherein the first body is composed at least in part of a firm polymeric material. 
     
     
       4. The apparatus of  claim 1  wherein the first body is composed at least in part of a porous polyurethane and a plurality of polyethylene stiffening beads embedded in polyurethane. 
     
     
       5. The apparatus of  claim 1  wherein the first body is further composed of abrasive particles fixedly bonded to the polyurethane at the planarizing surface. 
     
     
       6. The apparatus of  claim 1  wherein the finishing section comprises a napped material. 
     
     
       7. The apparatus of  claim 1  wherein the finishing section comprises a napped polyurethane. 
     
     
       8. The apparatus of  claim 1  wherein the backing film comprises a substantially incompressible copolymer. 
     
     
       9. The apparatus of  claim 1  wherein the backing film is sheet selected from one of a polyester and a polycarbonate. 
     
     
       10. The apparatus of  claim 1 , further comprising a second substrate holder positionable over the processing medium, the second substrate holder being positionable over one of the finishing section or the planarizing section when the first substrate holder is positioned over the other of the finishing section or the planarizing section, the first and second substrate holders contemporaneously planarizing and finishing at least two separate substrates on the planarizing and finishing sections of the processing medium. 
     
     
       11. The apparatus of  claim 1 , further comprising: 
       a supply roller around which a pre-operative portion of the processing medium is wrapped; and  
       a take-up roller around which a post-operative portion of the processing medium is wrapped, the processing medium being a web extending between the supply and take-up rollers so that an operative portion of the web is positioned on the support base, and the supply and take-up rollers being movable to incrementally advance the web across the support base.  
     
     
       12. The apparatus of  claim 11  further comprising a second substrate holder positionable over the processing medium, the second substrate holder being positionable over one of the finishing section or the planarizing section when the first substrate holder is positioned over the other of the finishing section or the planarizing section, the first and second substrate holders simultaneously planarizing and finishing at least two separate substrates on the planarizing and finishing sections of the web. 
     
     
       13. A planarizing machine, comprising: 
       a table with a support base;  
       a supply roller;  
       a take-up roller;  
       a processing medium having a first portion wrapped around the supply roller, a second portion wrapped around the take-up roller, and an operative portion positioned between the first and second portions and attached to the support base, the processing medium including a backing film, a planarizing portion coupled to one area of the backing film, and a finishing portion coupled to another area of the backing film adjacent to the planarizing portion, the planarizing portion having a planarizing surface structured to remove material from a substrate in the presence of a planarization liquid during a planarizing cycle, and the finishing portion having a finishing surface structured to buff the substrate during a finishing cycle; and  
       a carrier assembly having at least a first substrate holder and a second substrate holder, the first substrate holder being selectively positionable over one of the planarizing portion or finishing portion of the processing medium and the second substrate holder being positionable over the other of the planarizing portion or finishing portion of the processing medium, the first substrate holder translating a first substrate over the one of the planarizing portion or finishing portion of the processing medium and the second substrate holder contemporaneously translating a second substrate over the other of the planarizing portion or finishing portion of the processing medium to contemporaneously planarize and finish the first and second substrates.  
     
     
       14. The planarizing machine of  claim 13  wherein the backing film comprises a substantially incompressible copolymer. 
     
     
       15. The planarizing machine of  claim 14  wherein the backing film is selected from one of a polyester and a polycarbonate. 
     
     
       16. The planarizing machine of  claim 13  wherein the planarizing portion comprises a firm polymeric material. 
     
     
       17. The planarizing machine of  claim 13  wherein the planarizing portion comprises a suspension material and a plurality of abrasive particles fixedly bonded to the suspension material at the planarizing surface. 
     
     
       18. The planarizing machine of  claim 17  wherein the finishing portion comprises a napped polyurethane, the finishing portion being softer than the planarizing portion. 
     
     
       19. The planarizing machine of  claim 13  wherein the processing medium further comprises a ridge above the planarizing portion and finishing portions, the ridge partitioning the processing medium to prevent the planarizing liquid on the planarizing portion from mixing with a cleaning fluid on the finishing portion. 
     
     
       20. The planarizing machine of  claim 19  wherein the processing medium further comprises a channel extending along the bottom surface of the processing medium to receive the ridge for the first and second portions of the processing medium wrapped around the rollers. 
     
     
       21. A planarizing machine, comprising: 
       a table with a support base;  
       a supply roller;  
       a take-up roller;  
       a processing medium having a pre-operative portion wrapped around the supply roller, a post-operative portion wrapped around the take-up roller, and an operative portion positioned between the first and second portions and attached to the support base, the processing medium being a web including a planarizing zone with a planarizing surface and a finishing zone with a buffing surface adjacent to the planarizing zone, the planarizing surface being configured to remove material from a surface of one substrate in the presence of a planarizing liquid during a planarizing cycle, and the buffing surface being configured to clean another substrate during a contemporaneous finishing cycle; and  
       a carrier assembly having a first substrate holder positionable over one of the planarizing zone or the finishing zone and a second substrate holder contemporaneously positionable over the other of the planarizing zone and the finishing zone, wherein at least one of the processing medium and the first and second holders move to translate first and second substrates with respect to the planarizing and finishing zones.  
     
     
       22. The planarizing machine of  claim 21  wherein the planarizing zone is defined by a first body composed of, at least in part, a firm polymeric material. 
     
     
       23. The planarizing machine of  claim 22  wherein the first body comprises a suspension material and a plurality of abrasive particles bonded to the suspension material at the planarizing surface. 
     
     
       24. The planarizing machine of  claim 21  wherein the finishing zone is defined by a second body composed, at least in part, of a compressible material. 
     
     
       25. The planarizing machine of  claim 24  wherein the second body comprises napped polyurethane. 
     
     
       26. The planarizing machine of  claim 21 , further comprising a backing film attached to the planarizing and finishing zones. 
     
     
       27. The planarizing machine of  claim 21  wherein the processing medium further comprises a ridge extending above the planarizing zone and the finishing zone of the processing medium, the ridge partitioning the processing medium to prevent the planarizing liquid from mixing with a cleaning fluid.